Precision (repeatability and reproducibility) of ocular parameters obtained by the Tomey OA-2000 biometer compared to the IOLMaster in healthy eyes

Abstract

PurposeTo assess the precision (repeatability and reproducibility) of ocular parameters measured by the Tomey OA-2000 biometer, and to compare them with those measured by the IOLMaster.MethodsIn this prospective study, the right eyes of 108 healthy subjects were included. Three consecutive scans were obtained by 2 observers using the Tomey OA-2000, and in the same session one observer used the IOLMaster (version 5.4.4.0006) for the measurements. About 1 week later, 3 scans were obtained by one observer using the Tomey OA-2000. The axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), keratometer readings, pupil diameter (PD) and corneal diameter (CD) values measured by the Tomey OA-2000 and IOLMaster were analyzed. The coefficient of variation (CoV), intraclass correlation coefficient (ICC), within subject standard deviation (Sw) and 2.77Sw were calculated to assess the repeatability and reproducibility. The paired t test and Bland-Altman plots were used to analyze the differences and agreements of parameters measured by the two devices, respectively.ResultsIntraobserver repeatability, and interobserver and intersession reproducibility of the AL, CCT, ACD, LT, Kf, Ks, Km, PD and CD values measured by the Tomey OA-2000 biometer showed a CoV of less than 1% except that for PD, and an ICC of more than 0.97 except that for PD and CD. The AL, Kf, Ks, Km and CD values measured by the Tomey OA-2000 were 0.058 ± 0.094 mm, 0.088± 0.150 diopters (D), 0.163 ± 0.170 D, 0.127 ± 0.117 D and 0.171 ± 0.217 mm lower than those measured by the IOLMaster, respectively (all Ps < 0.05). However, the ACD values from the two devices were comparable (P = 0.169). The 95% linite of agreement (LoA) of the AL, ACD, CD and all keratometer readings were no more than 0.24 mm, 0.14 mm 0.60 mm and 0.5 D, respectively.ConclusionExcept for the PD and CD, the ocular parameters measured by the Tomey OA-2000 were highly repeatable and reproducible. Except for the CD value, there was good agreement of ocular parameters measured by the Tomey OA-2000 and the IOLMaster in healthy eyes.

Agreement of ocular biometric measurements in young healthy eyes between IOLMaster 700 and OA-2000

“…Kongsap et al 6 reported that the average difference in AL and ACD between OA-2000 and IOLMaster 500 in cataract patients were 0.06 mm and 0.21 mm respectively, which was statistically significant. Hua et al 10 also indicated that the AL and ACD values measured by Tomey OA-2000 and IOLMaster 500 were comparable in healthy eyes, with a mean difference of 0.058 ± 0.094 mm and 0.010 ± 0.075 mm (P < 0.05) and the 95% LoA no more than 0.24 mm and 0.14 mm, respectively. These differences between OA-2000 and IOLMaster 500 (PCI biometer) were more than our differences between OA-2000 and IOLMaster 700, suggesting that better agreement between the two SS-OCT in this study.…”

“…In this study all the K f measured by IOLMaster 700 were significantly higher than those measured by OA-2000. Previous study suggested that a difference of 1.0 D in keratometric value would cause a difference of about 1.40 D in the calculation of IOL power 10 . Accordingly, it could be inferred that the difference of 0.04 D in keratometric value would lead to a difference of about 0.06 D in IOL power calculation, which was far less than the increment of the IOL power step of 0.50 D. Meanwhile, the mean differences in J0 and J45 vector components of corneal astigmatism between the two biometers were 0.04 ± 0.57 D and −0.01 ± 0.59 D respectively, which were considered clinically negligible.…”

“…Recently, the optical biometric instruments IOLMaster 700 and OA-2000 have been applied in clinical practice, and a few studies have been conducted on these new instruments based on SS-OCT. Although it has been reported that either of instruments provides repeatable measurements with a deeper imaging range, less sensitivity reduction and faster scanning speeds [8][9][10][11] , there were no studies comparing the agreement between IOLMaster 700 and OA-2000 on ocular biometric parameters in subjects with transparent lens to date. We therefore performed an agreement analysis between the IOLMaster 700 and OA-2000 based on the definitions adopted by Bland and Altman recommended by the British standards body 12 .…”

Predictive accuracy of intraocular lens power calculation using applanation ultrasound biometry: can we still rely on ultrasound biometry?

“…The recent developments in phacoemulsification and IOL implantation in cataract and refractive lens surgery led to the promotion of accurate ocular biometry for the achievement of the predicted postoperative refractive outcomes (6). In this study, 59.4% of the eyes attained postoperative refraction within .5 D of refractive aim, which was statistically significant and above the 55% value established as the benchmark standard set by the National Health Service of the United Kingdom.…”

Intrasession Repeatability of Biometric Measurements Obtained with a Low-Coherence Interferometry System in Pseudophakic Eyes

“…This contrasts with the good levels of repeatability reported for crystalline lens thickness measurements with different optical biometers. 23,24 This may be a limitation that is present in pseudophakic eyes measured with this technology that should be investigated further. Indeed, statistically significant and clinically relevant differences have been found and reported when comparing lens thickness measurements obtained with ultrasound immersion and optical biometry.…”